C A S I A N A M U Ñ O Z - T U Ñ Ó N
&
A N T O N I A M . V A R E L A , J U L I O C A S T R O A L M A Z Á N
(
S K Y T E A M @ I A C . E S
)
The best skies for Astronomy
•
Sky transparency: Atmospheric extinction
•
Cloudiness (useful time)
•
Sky brightness
•
Ground base meteorology.
–
Long-term meteorological parameters
–
Climate variations
•
Seeing.
-Structure of the Atmospheric Turbulence
•
Precipitable Water Vapour (PWV)
•
Ground wind speed and direction, vertical
profile in the BL
•
Sodium layer density and height
•
Airborne aerosols and dust.
IAC 27/02/2014
CLEAR SKY
No clouds and High Transparency-Low Extinction
Kv monthly median
Kv yearly median fit=0.13
Useful time and extinction
The Carlsberg Meridian Telescope at the ORM since 1984 (
http://www.ast.cam.ac.uk
)
Weather downtime
AEMET Noviembre 2016
Average weather downtime : 23% (from a sample of 21 years)
18 yr WHT logs 26.33%
The Sky Quality Protection Technical
Office (OTPC) was set up by the IAC in
January 1992 to provide advice on the
application of the Sky Law (Law 31/1988),
http://www.iac.es/otpc
DARK SKY
Sky brightness using Photomultipliers tubes (185-830 nm) @ ORM&OT for six
different elevations// protocol to detect and control contaminating sources.
(see more at
http://www.iac.es/site-testing/
and
www.iac.es/OTPC
)
SKY BRIGHTNESS
IAC 27/02/2014 000001111111111111111111444444444444444444444444
Necesitamos... grandes espejos,
imágenes nítidas, que se pueden
mejorar... (AO)
C Muñoz-Tuñón, Backaskog september 2003
Differential Image
Motion Monitors
Sarazin & Roddier, 1990, A&A, 227, 294. (ESO DIMM)
Vernin & Muñoz-Tuñón, 1995, PASP, 107, 265 (DA/IAC DIMM)
Used by, GTC, TNG, O. Sierra Nevada, Calar Alto, ING,
INAOE (la Negra, Cananea), UNAM(Spedro M)...
Used in the FP6 site selection WP
Tower designed by the Galileo team
Integrated seeing (
ε
) statistics
Muñoz-Tuñón, Vernin & Varela, 1997, A&A Supp. S, 125, 183-193.
mean
0.76”
median
0.64” (0.54” in summer)
std
0.17”
< 0.3”
7%
On-line seeing data available
@ORM
www.iac.es/site-testing/DIMMA_ORM
Integrated seeing (
ε
)-
measured since 1995
(
DIMM- Vernin & Muñoz-Tuñón, 1995, PASP,107, 265
)
Squares: median values; Diamonds: mean values; Error bars STD of the mean.
Seasonal trend - seeing (
ε
)
Muñoz-Tuñón, Vernin & Varela, 1997, A&A Supp. S, 125, 183-193.
Behaviour coincident with the annual
Competition for hosting the E-ELT
Cumulative frequency of
!"""##$%$&'"()*"$$++",-../#-..01
Vernin & EELT team, PASP, 2011
Vázquez-Ramió & EELT team, PASP, 2012
/www.iac.es/site-testing/DIMMA_OT
ATST @HAWAII
AEMET Noviembre 2016
The gamma rays produce particle
showers in the atmosphere
CTA: Un esfuerzo a nivel mundial
cobertura de todo el cielo: dos observatorios
72.89.:;<0/8=/(
%./89.;(
>;<?9@9;(
%./89.;((
/A=2;>;<?9@9;(
B1C/2-;=,2.,(+,2=/(
B1C/2-;=,2.,(DE2(
F/G(G/(1;H;(/8/2>I;J(K(=/</C9,:.,C(>2;8G/C(
(L(5M(0/G.;8,C(
#,G,(/<(2;8>,(G/(/8/2>I;CJ(K((=/</C9,:.,C(
>2;8G/CN((3M(0/G.;8,C(L(O4(:/PE/Q,C(
•
"!#$%&%'%(')!
•
*+!,-.)')!
•
/0!123,$)!
•
+44!5%)&(3($)!
The technique works so we want bigger and
better! Cherenkov Telescope Array (CTA)
Northern site:
Observatorio del Roque de los Muchachos
(ORM/IAC), La Palma (Spain)
Southern site:
Large Size Telescopes (LST)
Artist: Akihiro Ikeshita (sponsored by ICRR, University of Tokyo)
23 m diameter
METEO data
Information Restricted Per Cover Page( TMT.XXX.XXX.XX.XXX.RELXX 36